Fluid drive and tool incorporating same



Oct. 18, 1960 IAN MUNRo YULE FLUID DRIVE AND TOOL. INCORPORATING SAMEOriginal Filed March 5, 1957 2 Sheets-Sheet 1 2- @T7-@CHESS Oct. 18,1960 :AN MuNRo YULE l 2,956,450

FLUID DRIVE AND TOOL INCORPORATING SAME Original Filed March 5, 1957 2Sheets-Sheet 2 O-AMW, @M w MM HTTOENEz/S- United States Patent O FLUIDDRIVE AND TOOL INCORPORATING SAME Ian Munro Yule, 145 Yamingale Road,Kings Heath, Birmingham 14, England Original application Mar. 5, 1957,Ser. No. 644,034. Divided and this application Mar. 24, 1959, Ser. No.801,603

Claims. (Cl. 74-7 30) This invention relates to a novel form of iuiddrive and also to a tool incorporating such uid drive.

This application is a division of my copending application Serial No.644,034, filed on March 5, 1957.

One object of the invention is to provide an improved uid drive having arequired degree of speed reduction between the two members (e.g. twoshafts), from one to the other of which the uid drive transmits rotarymotion.

Another object of the invention is to provide a fluid drive having aninitial high starting torque with uniform speed of rotation duringnormal running.

A further object of the invention is to provide a cornpact form of uiddrive for use where space is limited.

A still further object of the invention is to provide a form of uiddrive which will cushion any shocks, and which is also a nonpositivedrive.

The invention is illustrated in its various forms in the accompanyingdrawings which depict a tool for grinding annular valve seats andwherein:

Figure l is a side elevation of the tool.

Figure 2 is a section on the line 2-2 in Figure l.

Figures 3, 4, 5 and 6 are sections on the lines 3 3, 4 4, 5 5, and V6 6respectively in Figure 2.

Figure 7 is an exploded perspective view showing details of theepicyclic gearing for transmitting rotation to the locating sleeve.

The grinding tool shown in the accompanying drawings has a main outerbody portion 10 which is of hollow cylindrical form with a reducedcylindrical portion 11 at the lower end thereof and at the top there isprovided a finger grip member 12 having a circular flange by means ofwhich it is secured to the upper end of the body 10 using screws 14.

Within the body 10 there is an electric motor indicated diagrammaticallyat 15 to the armature of which is secured the grinding wheel shaft 17extending co-axially within the main body 11.

The upper end of the armature shaft at 18 has at its top a ball thrustbearing 19, below which is arranged a coiled compression spring 20 whichserves to urge the armature and grinding wheel shaft 17 upwardly topress the thrust bearing 19 against the underside of an adjustment cap21, which is secured to the member 12 by means of a screw 22, theperiphery 23 of the cap 21 being lcnurled so that it can be turnedeasily for the purpose of moving the grinding wheel shaft axiallyrelative to the body 10 so that the grinding wheel 24 which is carriedat the lower end of the shaft 17 can be adjusted for degree of cutrelative to the valve seat which is being ground.

A spring pressed ball 25 acts as a non-positive lock for retaining thecap 21 in any desired adjusted position.

Projecting endwise from the reduced portion of the body is an externallythreaded sleeve 26, this sleeve 26 being rotatable in the reducedportion 11 and the bore of the sleeve 26 is suitably lined to provide abearing for this end of the shaft 17.

2,955,450 Patented Oct. 18, 1960 ICC The locating sleeve has a main bodyportion 28 which is of cylindrical form and a frusto-conicalportion .29which engages the valve seat which is being ground and at the apex ofthis portion 29, there is a boss 30 within which is detachably securedby grub screw 31, a pilot shaft 32 which is adapted to engage in theVguide associated with the valve seat which is being ground.

The locating sleeve is formed at its upper end 33 with an opening ofcircular form which is eccentrically disposed in relation to the axis ofthe locating sleeve and pilot shaft 32, this circular opening beinginternally threaded so that it can be screwed upon the externallythreaded sleeve 26, in which position, as willg'be seen in Figure 2, theaxis of the pilot shaft 32 is'oiset from the axis of the grinding toolshaft 17. The locating sleeve is positioned on the externally threadedsleeve 26 by means of the internally threaded locking collar 27.

The bowed spring washer 61 acts to urge the sleeve 26 upwardly so thatthe ange 62 is thrust against the shoulder 63 on the interior of thereduced body portion 11. A thrust washer or rotary thrust race may beprovided at this position.

The locating sleeve is formed with an opening 34 which extends over thecylindrical portion 28 and the frustoconical portion 29 and it will beobserved that the periphery of the operative surface of the grindingwheel 24 is positioned in this opening 34 so that when the locatingsleeve is engaging a valve seat with its frusto-conical portion 29, theoperative surface of the grinding wheel :is also in engagement withthe'valve seat. The sleeve 29 locates the grinding wheel axially and incombination with the pilot shaft also locates'the grinding wheel in theradial direction.

Hence, when the locating sleeve is driven at a reduced speed from theelectric motor 15 through reduction gearing, which is hereinafterdescribed, the axis 17 of the grinding wheel is caused to traverse `in acircular path about the axis of the pilot shaft 32, thus traversing thegrinding wheel 24 around the valve seat and performing a grindingoperation on the eccentric grinding principle.

It will be observed that the grinding wheel, locating sleeve and pilotshaft are also detachable, so as to be capable of being-exchanged forcorresponding members of different sizes for dealing with various seatsof d iferent dimensions.

The grinding wheel shaft 17 is rotated at a speed of about 10,000r.p.rn. and the desired Vspeed of rotational traverse of thelocatingsleeve is about 2() rpm. so that it will be seen that a reductiongearing of 500 to 1 is required and the construction hereinafterdescribed obtains such a reduction gearing which is completely housedwithin the cylindrical body 10 without causing any enlargement of thediameter of the body.

Referring to Figure 2, the gearing is contained within an invertedcup-shaped housing 35 which is iitted nonrotatably within the outer body10 and is held in position by a spacer sleeve 36 which extends betweenthe top of the housing 35 and the underside of a shoulder 37 on thecasing of the electric motor. Apertures 38 through the body 10 andspacer sleeve 36 are provided to allow air to be drawn in by the motorcooling fan 39.

A roller bearing 40 is tted upon a downwardly projecting hollow boss 64formed integrally with the housing and a planet carrier 41 is rotatablymounted about the bearing 40, this planet carrier 41 having mountedthereon two planet pinions 42 which are 'situated at diametricallyopposed positions and lheld in place by an end plate 43 so as to becapable of free rotation about their axes which are spaced from andparallel to the axis of the shaft 17. (See now Figures 3 to 7).

Non-rotatably fitted within the cup-shaped housing 35 is an annular`gear ring 44 with which the pinions 42 plate 48 which is disposed in thebottom of the cylindrical body 10 and which is in driving engagementwith an extension 49, formed integrally with the sleeve 26. The drlvrngplate 48 has a central circular aperture provided with diametricallyopposed flats 50, which engage corresponding ats provided on the reducedupper end of the extension sleeve 49 so that the drive from the drivengearing 45 1s transmitted via the driving plate 48 to the extensions 49and thus to the locating sleeve 23.

The drive from the shaft 17 to the planet carrier 41 is auid'pressure-drive and for this purpose the underside of the planetcarrier 41 is formed with a circular recess 51 which contains a suitableoil, and the open end of this recess is closed by a dished end plate 52.Disposed within the recess 51 and keyed to the shaft 17 by a peg 53 isan impeller 54 in the form of a circular plate with minute teeth orserrations 55 on its perlphery. The wall 56 of the planet carrier whichsurrounds the recess 51 is provided with a number of radially extendingslots 57 in which are slidably mounted vanes 58 each such vane beingrelieved Slightly on its side faces, so as to allow oil from the recess51 to pass to the rear of the vanes 58. A raised shoulder 60 on the endplate 52 limits the extent of inwards travel of the vanes 58.

The operation of the reduction gearing is as follows: When the grindingtool is set up in position with the locating sleeve in a valve seat andthe electric motor is started the rotation of the impeller 54 causescirculation of the oil about the recess S1 and the increased pressureset up in the oil at the rear of each vane 58 causes these vanes to moveinwardly radially but as soon as the vanes project out of their slots57, they provide flat radial faces which form abutment surfaces for thecirculating oil and thus the oil commences to drive the planet carrier41. As the speed of rotation of the planet carrier 41 increases,centrifugal force acting on the vanes 58 overcomes the pressure actingat the back of each vane and the vanes gradually move outwardly untilonce more they are completely housed in their slots 57 and from thereonwards the planet carrier 41 is driven solely by the viscous drag ofthe oil upon the inner surface of the recess 51 and it is found topractice that the amount of slip which occurs in this uid drive issufiicient to give the desired reduction in drive between the impeller54 and the planet carrier.

The drive from the planet carrier 41 is then a normal epicyclicreduction drive via the planet pinions 42, the iixed annular ring 44 andthe driven ring 46.

For example the gearing can be constructed so as to give a reduction inthe fluid part of the drive of to 1 (i.e. the slip between impeller 54and planet carrier 41) and a reduction of 100 to l in the epicyclicgearing, thus giving an overall reduction of 500 to 1 which is requiredto drive the locating sleeve 28.

It will be appreciated that epicyclic gearing to give a reduction of 500to 1 in itself would involve rings of considerably larger diameter thanthose for giving a reduction of 100 to l, and this would mean that thebody of the tool would be too large and unwieldy for practical use.However, the provision of the fluid pressure drive and reduction in thisdrive permits an epicyclic gearing of a reasonable and practicaldiameter to be used so that the whole reduction gearing can beaccommodated within the connes of the cylindrical body 10.

Further, the fluid pressure part of the drive provides theinitial hightorque which is required for starting a rotation of the sleeve 28,because the vanes 58 all slide inwardly at the commencement of rotationto provide the positive abutment surface which enables the high torqueto be transmitted through the uid drive for the purpose of starting, andduring operation the ilexibility of the fluid Ydrive enables it tocushion any shocks which might be encountered through the locatingsleeve sticking or encountering any nuneven surfaces on the valve seator other obstruction tending to halt the traverse of the locatingsleeve.

Suitable oil seals are provided at various positions around the shaftl17 and also the oilv in the recess 51 may be used for lubricationpurposes by providing oil grooves extending axially through the sleeve49, 26 and return passage or passages along the shaft 17.

What I claim then is:

1. A fluid drive comprising a rotary driving member in the form of animpeller of generally circular cross section with its peripheral edgeportions having outwardly projecting portions, said impeller beingrotatably mounted in a housing containing a suitable uid, and a vanecarrier also rotatably mounted within the housing for rotation about theaxis of rotation of the impeller and `disposed so as to leave a uid-lledannular gap between the impeller and the vane carrier, said vane carrierhaving mounted therein a number of radially slidable vanes which arefree to move both inwardly into the annular gap under the influence offluid pressure in said annular gap and outwardly into the contines ofsaid vane carrier under the influence of centrifugal force.

2. A fluid drive according to claim 1 wherein the impeller comprises aflat disc having its periphery formed with serrations or teeth which aresmall in relation to the diameter of the disc, and wherein the vanecarrier comprises an annular ring'surrounding the impeller and having anumber of equi-angularly spaced radial slots in each of which isslidably mounted a vane, the radial side faces of the vanes beingrelieved so as to allow fluid to pass from the annular gap to the endfaces of the vanes.

3. A fluid drive in accordance with claim 1 in combination withepicyclic reduction gearing wherein the vane carrier is adapted to actalso as a planet carrier for the epicyclic gearing, a number of planetpinions being rotatably mounted in the carrier for rotation about axesparallel to the axis of rotation of the carrier, said planet pinion orpinions being in constant mesh with a non-rotatable annulus gear and a-rotatable driven annu- 4lus gear.

4. A fluid drive comprising a housing containing a suitable fluid, arotary driving member having outward projections formed `on itsperiphery and rotatably mounted in said housing, a vane carrier alsorotatably mounted in said housing, said vane carrier being disposed soas to leave a iluid filled annular gap between it and the rotary drivingmember, said vanecarrier having a number of radial slots contained in acommon plane and opening to said gap, a vane slidably mounted in each ofsaid slots, said vanes having relieved faces so that uid in said gap caniiow into the slots behind the vanes, each vane being free to slideinwards and outwards under the effects of centrifugal force and of uidpressure, dn've being transmitted from the rotary driving member to thevane carrier by the fluid and the vanes automatically positioningthemselves so as to maintain a constant speed ratio between the rates ofrotation of the vane carrier and the rotary driving member.

5. A fluid drive comprising a housing containing a suitable fluid, arotary driving member having outward projections formed on its peripheryand rotatably mounted in said housing, a vane carrier also rotatablymounted in said housing said vane carrier being disposed so as to leavea uid lled annular gap between it and the rotary driving member, saidvane carrier having a number of radial slots containedv in `a commonplane 6 opening to said gap, a vane slidably mounted in each tain 4aconstant speed ratio between the rates of rotation of said slots, saidvanes lhaving relieved faces so that of the vane carrier and the rotarydriving member. uid in said gap can ow into the slots behind the vanes,each vane being free to slide inwards and out- References Cited in the111e of this patent wards under the eects of centrifugal force and ofuid 5 pressure, each vane extending for the length of the vane UNITEDSTATES PATENTS carrier and being prevented from moving axially within2,400,186 Armentrollt May 14, 1946 the housing, drive being transmittedfrom the rotary driving member to the vane carrier by the uid and theFQREIGN PATENTS vanes automatically positioning themselves so as tomain- 10 505,413 Belglllm Sept. 15, 1951

